Automotive vehicles have been manufactured and sold in the United States with each of the following three systems:
(1) a PARK/LOCK which immobilizes the automatic transmission shift lever or the steering wheel of the vehicle, or both, until an ignition key has been inserted into the ignition lock and turned to release the PARK/LOCK; PA1 (2) a shifter interlock, traditionally, but not necessarily, tied into the brake light circuit of the vehicle to immobilize the shift lever for the automatic transmission and prevent its movement from the "PARK" position until the ignition circuit is activated and the brake pedal of the vehicle is depressed; and PA1 (3) an ignition key retention means to prevent the ignition lock from being turned from ON to LOCK while the vehicle is being actively driven.
Traditionally, these three systems have been essentially independent of one another. U.S. Pat. No. 4,474,085, issued Oct. 2, 1984 to DeVogelaere et al. and assigned to General Motors Corporation, illustrates a PARK/LOCK in which a cable extends from the ignition key lock to a bell crank associated with the shift lever release mechanism to prevent the release mechanism from being operated until such time as the ignition lock has been unlocked and turned. Shifter interlocks, typically brake/shifter interlocks, have been achieved using solenoids and electromagnets in a variety of ways to prevent operation of either the shift lever release mechanism or the shift lever itself until such time as the brake pedal is depressed to change the energization state of the brake/shifter interlock solenoid. Examples of electromagnetically operated brake/shifter interlocks are disclosed in U.S. Pat. Nos. 5,018,610, 5,009,295 and 5,167,308, issued May 28, 1991, Apr. 23, 1991 and Dec. 1, 1992 and assigned to Sparton Corporation, General Motors Corporation and Grand Haven Stamped Products Co.
Ignition key retention mechanisms are illustrated in U.S. Pat. Nos. 5,096,033 and 5,129,494, issued Mar. 17, 1992 and Jul. 14, 1992 and assigned to Grand Haven Stamped Products Company and Sparton Corporation.